code: def test_add(self):
      test_obj = object()
  
      self.assertFalse("test_obj" in self.cs)
  
      self.cs.add("test_obj", "Test object", test_obj)
  
      self.assertTrue("test_obj" in self.cs)
  
      self.assertEqual(len(self.cs), 1)
      self.assertEqual(list(self.cs), [("test_obj", test_obj)])
  
      self.assertEqual(self.cs.test_obj, test_obj)
      self.assertEqual(self.cs["test_obj"], test_obj)
  
file_path: MONAI/tests/test_component_store.py
imports: from __future__ import annotations
  import unittest
  from monai.utils import ComponentStore
label_desc: Use image node_id 3 for calling the TestComponentStore obj's underlying member method code with example usage: obj.test_add() without return types